In the past, ethynyl carbinols of the formula: ##STR1## wherein R.sub.1 is lower alkyl, lower alkenyl or hydrogen; R.sub.2 is hydrogen or a hydrocarbon having from 1 to 18 carbon atoms; R.sub.1 and R.sub.2 taken together with their attached carbon atom form a cyclic member selected from the group consisting of cyclo lower alkyl, or cyclo lower-alkenyl; and R and R.sub.3 are lower alkyl, lower alkenyl or hydrogen;
Have been formed by reacting a compound having the formula: ##STR2## wherein R, R.sub.1, R.sub.2 and R.sub.3 are as above;
With sodium acetylide. See J.A.C.S. 57, p. 340, (1935) and J.A.C.S. 66, 1289, (1944). The use of sodium acetylide has proven disadvantageous since the yields of the compound of formula I have been low. In U.S. Pat. No. 2,425,201, Oroshnik, Aug. 5, 1947, the use of calcium acetylide for carrying out this process is disclosed. Furthermore, in Oroshnik et al. J.A.C.S. 71, 2062, (1949) the use of acetylides such as lithium acetylide, calcium acetylide and potassium acetylide for carrying out this process has been disclosed. However, these acetylides have proven to be very expensive. Furthermore, when these acetylides are utilized in this process, the compound of formula I is produced together with various side products and tars which are difficult to separate from the compound of formula I. Therefore, a more economical acetylide which will produce the compound of formula I in high yields without difficulty separable tars and side products has been long desired in the art.
The compound magnesium acetylide has been a compound that has been very hard to prepare owing to the difficulty of solubilizing magnesium and its acetylide in conventional solvents.